DEMO MANUAL DC2160A
LTC4419
18V Dual Input Micropower
PowerPath™ Prioritizer
DESCRIPTION
Demonstration circuit 2160A uses the LTC®4419 to
provide backup switchover, keeping the output load
powered during brown out or power loss conditions.
Priority is assigned by supply connection to the V1 and
V2 inputs. The power source connected to V1 has a higher
priority and is monitored by undervoltage switchover
threshold comparator CADJ (pin ADJ). If V1 exceeds
1.55V and ADJ is above 1.097V for 64ms, V1 is considered
valid, and the LTC4419 connects V1 to the load. If V1
drops below 1.52V, or ADJ drops below 1.047V, V1 is
considered invalid, and the LTC4419 powers the load
from V2. The DC2160A is populated to provide switchover
when V1 drops below 10.19V ±0.33V. The upper limit for
V1 is the maximum operating voltage, 18V; however, the
recommended V1 voltage is 12V. The resistive divider (R1R2) of the first auxiliary comparator CMP1 is adjusted to
trigger the comparator when VCMP1_TOP’s voltage is in
the 9.92V to 10.74V range. Practically, any voltage from
the operating range can be selected for V2, however, 5V
is recommended to have a standard voltage level.
PERFORMANCE SUMMARY
The second auxiliary comparator CMP2 divider (R8-R7) is
adjusted to trigger the comparator when VCMP2_TOP’s
voltage is in the 3.26V to 3.53V range. Overcurrent (0.5A
to 1.6A) and thermal protection inherent to the LTC4419
allows safe prioritization. Overtemperature protection is
activated when the junction temperature exceeds 125ºC.
Another inherent feature – reverse supply protection –
protects the prioritizer and load when a negative voltage
(up to –15V) is applied to any input – V1 or V2.
The LTC4419’s “break-before-make” switching method
prevents cross conduction between input channels. The
LTC4419 does not connect any input source to the load
until the input voltage exceeds the output by 50mV. This
eliminates reverse current from the output into the selected
input supply.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2160A
L, LT, LTC, LTM, Linear Technology, and the Linear logo are registered trademarks and
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
Specifications are at TA = 25°C
SYMBOL
PARAMETER
V1, V2, VOUT
V1, V2, VOUT Operating Supply Range
CONDITIONS
RON
Switch Resistance
V1 = V2 = 5V, IOUT = –100μA
MIN
TYP
1.8
1
2
MAX
UNITS
18
V
5
Ω
ms
tVALID(V1)
Input Qualification Time
V1 Rising, ADJ Rising
VTHA
ADJ Threshold
ADJ Falling
34
64
94
1.032
1.047
1.062
VHYSTA
ADJ Comparator Hysteresis
ADJ Rising
30
50
70
VTHC
CMP1, CMP2 Threshold
CMP1, CMP2 Falling
0.378
0.387
0.396
V
VHYSTC
CMP1, CMP2 Hysteresis
CMP1, CMP2 Rising
7.5
10
12.5
mV
ILIM
Current Limit
V1 = V2 = 8.4V
0.5
1.1
1.6
A
VREV
Reverse Comparator Threshold
(V1, V2) – VOUT for Power Path Turn-On
25
50
75
mV
tSWITCH
Switch Break-Before-Make Time
V1 = V2 = 5V, IOUT < –10mA
1
2.5
5
µs
V1_SWITCHOVER
Demo Board Switchover Voltage
9.6
9.92
10.24
V
V1_ALARM
Demo Board V1 Alarmed Voltage
9.92
10.32
10.74
V
V2_ALARM
Demo Board V2 Alarmed Voltage
3.26
3.38
3.53
V
V
mV
dc2160af
1
DEMO MANUAL DC2160A
OVERVIEW
The DC2160A includes the LTC4419 2-input prioritizer (U1), LDO regulator with 2.5V output voltage
(U2‑LT1763) for powering LEDs and logic, four LEDs
(D4-D7) for visual information, two jumpers (JP1, JP2)
for selecting the power source for the LDO, push button (SW1) for engaging freshness seal mode, and a few
turrets for connecting the board to power sources, load
and measuring instrument. Auxiliary components—LDO
and logic—are placed on the bottom side of board.
The DC2160A design permits operation of each channel
over its full operating voltage range.
Provision is made for increasing the hysteresis of auxiliary comparator 1 and auxiliary comparator 2 by placing
optional resistors R17/R19.
TURRETS
V1 (E1): 12V supply input; should not exceed +18V, and
should be larger than –15V.
CMP1 (E4): First auxiliary comparator CMP1 non-inverting
input.
V2 (E8): 5V supply input; should not exceed +18V, and
should be larger than –15V.
CMP2 (E6): Second auxiliary comparator CMP2 noninverting input.
ADJ (E3): Adjustable comparator non-inverting input for
setting switchover threshold level.
GND (E5, E11, and E12): Common ground terminal.
VCMP1_TOP (E2): Input for voltage monitored by first
auxiliary comparator CMP1.
LDO_EXT (E13): Positive terminal for external auxiliary
3.5V to 20V power supply.
VCMP2_TOP (E7): Input for voltage monitored by second
auxiliary comparator CMP2.
OUT (E9): Output for up to 2A load.
V2P5V (E10): LDO output voltage terminal (2.5V).
JUMPERS
JP1, LDO: ON/OFF switch for LDO.
JP2, LDO_POWER: Power supply selection for LDO.
LEDS
D4: Indicates LDO output voltage.
D5: Indicates first auxiliary comparator output stage
(CMPOUT1 pin).
2
D6: Indicates second auxiliary comparator output stage
(CMPOUT2 pin).
D7: Indicates powering load from V2 source.
dc2160af
DEMO MANUAL DC2160A
QUICK START PROCEDURE
Refer to Figure 1 for proper measurement equipment setup
and follow the procedure below:
1.097V and when the output voltage starts to rise. The
qualification time should be in the range 34ms to 94ms.
1.Place JP1 in position ON and JP2 in position EXTER_
POWER. Turn off all external switches SW1-SW4.
Connect turrets ADJ and GND with external wire.
5.Turning SW1 off or decreasing V1 to 9V initiates switchover from V1 to V2. Turning SW1 back to on or
increasing V1 above 10.5V initiates switchover from
V2 to V1 with a qualification time delay.
2.Adjust V1 supply output to 12.0V, V2 to 5V, and auxiliary
power supply to 10V. Use 30Ω resistive load.
3.Turn all external switches SW1-SW4 on.
4.Place scope probes at the ADJ and OUT turrets. Disconnect the turrets ADJ and GND and measure the time
between events when the ADJ pin voltage reaches
6.Turn all external switches SW1-SW4 off again and connect
turrets ADJ and GND with external wire. Use 5Ω resistive
load. Place current probe to measure load current.
7.Turn all external switches SW1-SW4 on. Disconnect the
turrets ADJ and GND and observe overcurrent transients
with cooling period and thermal protection.
Figure 1. Proper Measurement Equipment Setup
dc2160af
3
DEMO MANUAL DC2160A
PARTS LIST
ITEM
QTY
1
4
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
0
BT1
HOLDER, BATTERY 20mm OPTION
KEYSTONE 1066 OPTION
2
2
COUT1,COUT
CAP, 1206 10μF 20% 25V TANT
AVX F951E106MAAAQ2
3
3
C1, C2, C7
CAP, 2220 47uF 20% 25V X5R
TDK CKG57NX5R1E476M500JH
4
0
C3, C4, C5, C6
CAP, 1206 OPTION
OPTION
5
0
C8
CAP, 2220 OPTION
OPTION
6
2
C9, C10
CAP, 0805 0.1μF 10% 25V X5R
AVX 08053C104KAT2A
7
1
C11
CAP, 0805 10nF 10% 16V X7R
AVX 0805YC103KAT2A
8
0
C13
CAP, 0805 1nF 10% 50V X7R OPTION
AVX 08055C102KAT OPTION
9
1
C14
CAP, 7343 10μF 10% 35V TANT
AVX TPSD106K035R0300
10
2
D1, D2
DIODE, 400 WATT TRANSIENT VOLTAGE
SUPPRESSOR
LITTELFUSE INC. SMAJ18CA
11
1
D3
DIODE, 400 WATT TRANSIENT VOLTAGE
SUPPRESSOR
LITTELFUSE INC. SMAJ18A
12
1
D4
LED, 0603 GREEN
WURTH ELEKTRONIK 150060GS75000
13
1
D5
LED, 0603 BLUE
WURTH ELEKTRONIK 150060BS75000
14
1
D6
LED, 0603 YELLOW
WURTH ELEKTRONIK 150060YS75000
15
1
D7
LED, 0603 YELLOW ORANGE
LITEON LTST-C190KFKT
16
6
E1, E8, E9, E11, E12, E13
TURRET
MILL-MAX 2501-2-00-80-00-00-07-0
17
7
E2, E3, E4, E5, E6, E7, E10
TURRET
MILL MAX 2308-2-00-80-00-00-07-0
18
2
JP1, JP2
HEADER, 2mm, 3-PIN
WURTH 62000311121
19
4
MH1, MH2, MH3, MH4
STANDOFF, SNAP ON
KEYSTONE_8831
20
1
R1
RES, 0805 1.21M PHMS 1% 1/18W
VISHAY CRCW08051M21FKEA
21
2
R2, R7
RES, 0805 47.5k 5% 1/8W
VISHAY CRCW080547K5FKEA
22
1
R3
RES, 0805 1M 1% 1/8W
VISHAY CRCW08051M00FKEA
23
1
R4
RES, 0805 118k 1% 1/8W
VISHAY CRCW0805118KFKEA
24
0
R5
RES, 0805 69.8k 1% 1/8W OPTION
VISHAY CRCW080569K8FKEA OPTION
25
0
R6
RES, 0805 OPTION
OPTION
26
1
R8
RES, 0805 365k 1% 1/8W
VISHAY CRCW0805365KFKEA
27
2
R9, R10
RES, 0805 511k 1% 1/8W
VISHAY CRCW0805511KFKEA
28
3
R11, R12, R13
RES, 0805 200Ω 1% 1/8W
VISHAY CRCW0805200RFKEA
29
2
R15, R16
RES, 0805 2Ω 1% 1/8W
VISHAY CRCW08052R00FKEA
30
0
R17, R19
RES, 0805 1M 1% 1/8W OPTION
VISHAY CRCW08051M00FKEA OPTION
31
1
R18
RES, 0805 510Ω 5% 1/8W
VISHAY CRCW0805510RJNEA
32
1
SW1
SWITCH, MOMENTARY, PUSH BUTTON
WURTH 434 123 050 816
33
1
U1
IC, LTC4419IDD#TRPBF
LINEAR TECH LTC4419IDD#TRPBF
34
1
U2
IC, 500mA LOW NOISE LDO
MICROPOWER REGULATOR
LINEAR TECH LT1763CS8-2.5#PBF
35
1
U3
IC, LOW-POWER TRIPLE INVERTER
BUFFER/DRIVER
TEXAS INSTRUMENTS
SN74AUP3G06DCUR
36
2
XJP1, XJP2
SHUNT, 2mm
WURTH 60800213421
dc2160af
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
A
B
C
D
E8
E7
E6
E5
E4
E3
D1
SMAJ18CA
-
+
R16
2
1%
C2
47uF
25V
2220
SMAJ18CA
D2
R8
365k
1%
R2
47.5k
1%
R1 1.21M
C3
OPT
1206
C5
OPT
1206
R7
47.5k
1%
R6
OPT
OUT
R5
OPT
5
1. ALL RESISITORS AND CAPACITORS ARE 0805.
NOTES: UNLESS OTHERWISE SPECIFIED,
BT1
3.6V
OPT
1.7V-18V
V2
VCMP2_TOP
CMP2
GND
CMP1
ADJ
VCMP1_TOP
R15
2
1%
C1
47uF
25V
2220
E2 VCMP1_TOP UVLO RANGE 10.30V-11.24V
1.7V-18V
V1
C6
OPT
1206
R4
118k
1%
R3
1M
1%
C4
OPT
1206
4
1
9
2
V2
CMP2
CMP1
ADJ
V1
OPT
R19
ADDS HYSTERESIS
TO CMP2
OPT
R17
ADDS HYSTERESIS
TO CMP1
0.1uF
C10
10
C13
1nF
OPT
3
C9
0.1uF
U1
7
6
5
SW1
PUSH FOR
FSEAL
V2ON
TP2
JP1
3
2
C14 +
10uF
1 35V
OUT
5
8
SHDN
IN
3
6
1
2A
3A
1A
3
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
5
2
CMP2
HIGH
D6
YELLOW
CMP1
HIGH
D5
BLUE
SCALE = NONE
2
1
10uF
1206
E12
E11
E10
GND
GND
V2P5V
LDO_EXTER
OUT
2A
E13
+ COUT
E9
1
SHEET 1
LTC4419IDD#TRPBF
DEMO CIRCUIT 2160A
4
OF 1
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
2-INPUT PRIORITIZER
IC NO.
DATE: Tuesday, May 05, 2015
N/A
SIZE
TITLE: SCHEMATIC
TECHNOLOGY
OUT
FROM
V2
D4
GREEN
2.5V UP
D7
YELLOW ORANGE
R13
200
V2P5V
10uF
1206
R18
510
D3
SMAJ18A
SMA
+ COUT1
CMPOUT2
TP4
R10
511k
1%
R12
200
R9
511k
1%
C8
OPT
2220
R11
200
CMPOUT1
TP3
10nF
C11
U3 SN74AUP3G06DCUR
2Y
3Y
1Y
7
4
2
C7
47uF
2220
V2P5V
2
APPROVALS
V2P5V
BYP
SENSE/ADJ
OUT
1
U2 LT1763CS8-2.5#PBF
CUSTOMER NOTICE
OFF
ON
LDO
JP2
3
2
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
V2ON
CMPOUT2
CMPOUT1
OUT
8
EXTER_POWER
LTC4419IDD#TRPBF
1
LDO_POWER
OUT
GND
3
3
GND
6
E1
4
GND
11
GND
4
GND
7
8
VCC
GND
4
5
A
B
C
D
DEMO MANUAL DC2160A
SCHEMATIC DIAGRAM
dc2160af
5
DEMO MANUAL DC2160A
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application
engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
6
dc2160af
Linear Technology Corporation
LT0816 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
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